Sex and Hormones Flashcards
Lecture 17 (29 cards)
What prevents a male embryo to develop into a female embryo?
Mullerian inhibiting hormone (MIH)
Two chemical categories during development
Androgen and estrogen
What does sexual differentiation depend on during sensitive period?
Mostly on the level of testosterone during a sensitive period
When does the ‘sensitive period’ for genital formation occur?
Third and fourth month of pregnancy
True or False: Does extra estradiol (estrogen) hormone determine whether the individual looks female or male?
False: Extra estradiol does NOT determine whether the individual looks female or male however, they do modify various aspects of the developing brain and internal sexual organs
What is the sexual dimorphic nucleus?
It is an area in the anterior hypothalamus that is larger in the male. It contributes to control male sexual behavior.
What can the hypothalamus of female do that the male cannot?
Parts of the female hypothalamus can be much larger which generates a cyclical pattern of hormone release (used during menstruation)
“Sex differences” vs “Gender differences”?
- Sex differences: biological differences
- Gender differences: individual’s thoughts about themselves
What is an intersex individual?
Intersex individuals are people that have anatomies intermediate between male or female (used to be called hermaphrodites)
What occurs in Congenital Adrenal Hyperplasia (CAH)?
Most common cause of intersex. When cortisol production leads to overstimulation of the adrenal gland causes extra testosterone production.
What is Androgen Insensitivity?
Aka testicular ferminization is a condition in which individuals with an XY chromosome pattern (male) have the genital appearance of a female.
What causes Androgen Insensitivity?
These individuals produce they produce normal androgen but they do not have enough androgen receptors preventing the androgen from going into cells and activating cell’s nucleus
Whats is Dihydrotestosterone (DHT)?
It is the most effective hormone at masculinising the external genitals
Do hormones cause behavior?
Hormones do NOT cause behavior but rather alter the activity in various brain areas to change the way the brain responds to certain stimuli (which may or may not result in a behavior)
What areas of the brain can sex hormones turn on (stimulate)?
The hypothalamus: the ventromedial nucleus (VMN), the medial preoptic area (MPOA), and the anterior hypothalamus
Estrogens increases sensitivity of the pudendal nerve. What is the pudendal nerve?
The pudendal nerve transmits tactile stimulation from the vagina and cervix to the brain
Testosterone increases the release of nitric oxide. What is nitric oxide?
Nitric oxide increases blood flow to the penis, causing an erection
What does Viagra do?
Viagra prolongs the effect of nitric oxide which increases blood flow to the penis, causing an erection
What are the effects of. serotonin on dopamine?
Serotonin activity decreases sexual activity by blocking dopamine release
What is impotence?
Impotence is the inability to maintain an erection usually caused by impaired blood circulation, NOT low testosterone
What is follicle-stimulating hormone (FSH)?
FSH is released by the anterior pituitary. FSH promotes growth of follicle in ovary. The follicles nurtures the ovum and produces estrogen.
What is the importance of the follicle in the ovary?
The follicle nurtures the ovum and produces estrogen.
After the end of menstrual cycle:
- Anterior pituitary releases follicle-stimulating hormone (FSH)
- FSH promotes growth of follicle in ovary
The follicle nurtures the ovum and produces estrogen
Towards the middle of the menstrual cycle:
- The follicle builds up receptors to FSH
- As a result, the follicle produces increasing amounts of estradiol back up to the brain
